Visual Contrast Research Articles

Eye Adult Changes in Thought (Eye ACT) Study: Design and Report on the Inaugural Cohort.

Conflicting research on retinal biomarkers of Alzheimer's disease and related dementias (AD/ADRD) is likelyrelated to limited sample sizes, study design, and protocol differences. The prospective Eye Adult Changes in Thought (Eye ACT) seeks to address these gaps. Eye ACT participants are recruited from ACT, an ongoing cohort of dementia-free, older adults followed biennially until AD/ADRD, and undergo visual function and retinal imaging assessment either in clinic or at home. 330 participants were recruited as of 03/2023. Compared to ACT participants not in Eye ACT (N = 1868), Eye ACT participants (N = 330) are younger (mean age: 70.3 versus 71.2, p = 0.014), newer to ACT (median ACT visits since baseline: 3 versus 4, p < 0.001), have more years of education (17.7 versus 16.2, p < 0.001) and had lower rates of visual impairment (12% versus 22%, p < 0.001). Compared to those seen in clinic (N = 300), Eye ACT participants seen at home (N = 30) are older (77.2 versus 74.9, p = 0.015), more frequently female (60% versus 49%, p = 0.026), and have significantly worse visual acuity (71.1 versus 78.9 Early Treatment Diabetic Retinopathy Study letters, p < 0.001) and contrast sensitivity (-1.9 versus -2.1 mean log units at 3 cycles per degree, p = 0.002). Cognitive scores and retinal imaging measurements are similar between the two groups. Participants assessed at home had significantly worse visual function than those seen in clinic. By including these participants, Eye ACT provides a unique longitudinal cohort for evaluating potential retinal biomarkers of dementia.

QOL-46. EFFECTIVENESS OF A TELEREHABILITATION PROGRAM TO IMPROVE VISUAL PERCEPTION IN CHILDREN AND ADOLESCENTS WITH HEMIANOPIA CONSECUTIVE TO A BRAIN TUMOUR

Abstract BACKGROUND Brain tumours in children often lead to visual impairment, which presents as a significant morbidity for long-term survivors. A recent Children Cancer Survivor Study showed that 22.5% of the patients with astroglial tumours had visual impairment five years after the diagnosis. In the pediatric population with hemianopia, there are no standardized protocols for managing vision loss. This study evaluated a 6-week home-based telerehabilitation program (home-based 3D-MOT-IVR) on visual perception in children with hemianopia consecutive to a brain tumour. METHODS This phase 2a, open-labelled, non-randomized, single-arm study included ten patients aged 12-18 years old with hemianopia consecutive to a pediatric brain tumour. Patients followed a 6-week home-based 3D-MOT-IVR with remote control of the device from the UHN laboratory. Visual assessments were performed at baseline, 2, 4, and 6 weeks, with follow-ups at 1 and 6 months to check the visual field, contrast sensitivity and reading speed. RESULTS The home-based 3D-MOT-IVR intervention proved feasible and safe, with no reported adverse events. All participants completed the prescribed stimulations, pre- and post-intervention assessment points, and 90% completed the follow-ups. Remarkably, the outcomes revealed significant improvements post-intervention: 50% of participants showed enhanced visual perception in their blind field, while 70% exhibited increased reading speed. Importantly, these positive effects were sustained at the 6-month follow-up. A robust correlation emerged between 3D-MOT-IVR performance and improved visual perception in the blind field, emphasizing the intervention’s effectiveness. CONCLUSION These promising results lay a strong foundation for a larger randomized controlled trial, offering hope for a meaningful breakthrough in visual rehabilitation for this vulnerable population. Further studies are being developed to confirm these results and identify the most appropriate schedules to optimize visual outcomes (such as duration and repetition of these programs).

Hazard Perception in Visually Impaired Drivers Who Use Bioptic Telescopes.

Bioptic telescopic spectacles can allow individuals with central vision impairment to obtain or maintain driving privileges. The purpose of this study was to (1) compare hazard perception ability among bioptic drivers and traditionally licensed controls, (2) assess the impact of bioptic telescopic spectacles on hazard perception in drivers with vision impairment, and (3) analyze the relationships among vision and hazard detection in bioptic drivers. Visual acuity, contrast sensitivity, and visual field were measured for each participant. All drivers completed the Driving Habits Questionnaire. Hazard perception testing was conducted using commercially available first-person video driving clips. Subjects signaled when they could first identify a traffic hazard requiring a change of speed or direction. Bioptic drivers were tested with and without their bioptic telescopes in alternating blocks. Hazard detection times for each clip were converted to z-scores, converted back to seconds using the average response time across all videos, and then compared among conditions. Twenty-one bioptic drivers and 21 normally sighted controls participated in the study. The hazard response time of bioptic drivers was improved when able to use the telescope (5.4 ± 1.4 seconds vs 6.3 ± 1.8 seconds without telescope); however, it remained significantly longer than for controls (4.0 ± 1.4 seconds). Poorer visual acuity, contrast sensitivity, and superior visual field sensitivity loss were related to longer hazard response times. Drivers with central vision loss had improved hazard response times with the use of bioptic telescopic spectacles, although their responses were still slower than normally sighted control drivers. The use of a bioptic telescope by licensed, visually impaired drivers improves their hazard detection speed on a video-based task, lending support to their use on the road.

The impact of vision loss on attitudes toward autonomous vehicles: A vision-centric analysis.

Autonomous vehicles (AVs) have the promise to be an alternative transportation solution for those with vision loss. However, the impact of vision loss on the perceptions and concerns of AVs is unknown. This study therefore examined whether AVs are perceived differently by blind, visually impaired (VI), and normally sighted people. This study compared the perceptions of AVs among the blind, VI, and normally sighted. Participants' opinions on four perception measures (general opinion, trust, impact on quality of life, and intention to use AVs) and nine concerns regarding AVs were measured. The survey was administered to 51 normally sighted, 68 VI, and 65 blind participants. Analyses of covariance assessed whether the four perception measures and nine concerns varied by vision status (normal vision, VI, blind) and driving status (driver, nondriver). Univariate correlations and multiple regression analyses identified associations and predictors of AV perceptions and concerns from demographic, mood, cognition, travel behavior, and vision measures, which included visual acuity, contrast sensitivity, and visual field. The blind (p<0.001), VI (p<0.001), and nondrivers (p<0.001) showed a greater intention to use AVs compared with those with normal vision and drivers. Similar findings were found for the other perception measures. As visual acuity, contrast sensitivity, and visual field extent declined, positivity toward AVs increased (p<0.001). Visual field extent best predicted general opinion and trust in AVs, whereas driving measures were the best predictors of impact on quality of life and intention to use AVs. Concerns about AVs showed no differences based on vision (p=0.94) or driving (p=0.63) status. Individuals with vision loss expressed more acceptance of AVs despite their concerns. How positive someone is toward AVs appears to be dependent on their visual field extent and driving status.

P‐115: The Optimized Method for Sparkle Contrast Measurement of Anti‐Glare Covered Vehicle Display

We have presented an optimized method for evaluating the visual sparkle contrast of anti‐glare covered vehicle display and compared the results to standard measurement conditions. By assessing the sparkle contrast changes under different ambient light conditions and different viewing angle conditions, and analyzing the results, we provide measurement recommendations for the sparkle rating evaluation of vehicle display.

Vision-related quality of life, photoaversion, and optical rehabilitation in achromatopsia.

We report on photoaversion and patient-reported quality of life in Danish patients with achromatopsia and evaluate the best optical rehabilitation. Our results contribute to the evaluation of outcome measures in therapy trials and aid in providing the best optical rehabilitation for patients with this and clinically similar conditions. This study aimed to investigate the vision-related quality of life, the impact of photoaversion on daily living, and the best optical rehabilitation in a cohort of achromatopsia patients, including testing the hypothesis that red light-attenuating filters are generally preferred. Patients with genetically verified achromatopsia were recruited. Investigations included the 25-item Visual Function Questionnaire and supplementary questions regarding photoaversion and visual aids. Patients were evaluated by a low vision optometrist and given the choice between different light-attenuating filters. First, two specially designed red and gray filters both transmitting 6% light, and then a pre-defined broader selection of filters. Best-corrected visual acuity and contrast sensitivity were measured without filters and with the two trial filters. Twenty-seven patients participated. Median 25-item Visual Function Questionnaire composite score was 73, with the lowest median score in the subscale near vision (58) and the highest in ocular pain (100). The majority of patients (88%) reported that light caused them discomfort, and 92% used aid(s) to reduce light. Ninety-six percent (26 of 27) preferred the gray filter to the red indoors; 74% (20 of 27) preferred the gray filter. Contrast sensitivity was significantly better with the gray filter compared with no filter (p=0.003) and the red filter (p=0.002). Our cohort has a relatively high vision-related quality of life compared with other inherited retinal diseases, but photoaversion has a large impact on visual function. Despite what could be expected from a theoretical point of view, red filters are not generally preferred.

Concordance between Self-Reported Visual Difficulty and Objective Visual Impairment: The National Health and Aging Trends Study

ObjectiveTo examine the performance of self-reported visual difficulty (VD) in predicting objective visual impairment (VI) in older adults and explore factors that influence discordance in these classifications. DesignCross-sectional analysis of the National Health and Aging Trends Study (2022). MethodsParticipants reporting blindness or difficulties with distance or near vision were characterized as having VD. Presenting binocular distance visual acuity (VA), near VA, and contrast sensitivity (CS) were assessed. Objective VI was defined as having VI in either distance VA (worse than 20/40), near VA (worse than 20/40), or CS (worse than 1.55 logCS). Receiver operating characteristic analysis was used to compare performance of VD in predicting objective VI. To investigate factors that influence discordance, we limited our sample to adults with objective VI and employed a multivariable logistic regression model to identify factors associated with not reporting VD. Similar analyses were performed to explore factors associated with reporting VD in adults without objective VI. Results4,999 adults were included in the 2022 cohort. VD achieved an area under the curve (AUC) of 56.0 (95% CI: 55.2, 56.9) in predicting objective VI, with a sensitivity of 15.8 (95% CI: 14.2, 17.5) and specificity of 96.3 (95% CI: 95.5, 96.9). Characteristics associated with not reporting VD in adults with objective VI included: female gender (odds ratio [OR]: 0.64 [95% CI: 0.42, 0.99]), Hispanic ethnicity (OR: 0.49 [95% CI: 0.31, 0.78), higher income (≥75k, OR: 1.99 [95% CI: 1.14, 3.45]), having ≥4 comorbidities (OR: 0.46 [95% CI: 0.29, 0.72]), and having depressive symptoms (OR: 0.49 [95% CI: 0.25, 0.93]). Meanwhile, factors associated with self-reporting VD in the absence of objective VI included Hispanic ethnicity (OR: 2.11 [95% CI: 1.15, 3.86]), higher income (≥75k, OR: 0.27 [95% CI: 0.12, 0.63]), and having anxiety symptoms (OR: 3.05 [95% CI: 1.56, 5.97]). ConclusionsSelf-reported visual difficulty is a distinct measure assessing disability and has limited ability in predicting objective VI. Caution is advised when utilizing self-reported visual difficulty as a surrogate measure for objective VI in epidemiological studies, though it may still be an effective way to capture risk of current or future disability.

An ethologically relevant paradigm to assess defensive response to looming visual contrast stimuli

In the animal kingdom, threat information is perceived mainly through vision. The subcortical visual pathway plays a critical role in the rapid processing of visual information-induced fear, and triggers a response. Looming-evoked behavior in rodents, mimicking response to aerial predators, allowed identify the neural circuitry underlying instinctive defensive behaviors; however, the influence of disk/background contrast on the looming-induced behavioral response has not been examined, either in rats or mice. We studied the influence of the dark disk/gray background contrast in the type of rat and mouse defensive behavior in the looming arena, and we showed that rat and mouse response as a function of disk/background contrast adjusted to a sigmoid-like relationship. Both sex and age biased the contrast-dependent response, which was dampened in rats submitted to retinal unilateral or bilateral ischemia. Moreover, using genetically manipulated mice, we showed that the three type of photoresponsive retinal cells (i.e., cones, rods, and intrinsically photoresponsive retinal ganglion cells (ipRGCs)), participate in the contrast-dependent response, following this hierarchy: cones > > rods > > > ipRGCs. The cone and rod involvement was confirmed using a mouse model of unilateral non-exudative age-related macular degeneration, which only damages canonical photoreceptors and significantly decreased the contrast sensitivity in the looming arena.

State-Dependent tACS Effects Reveal the Potential Causal Role of Prestimulus Alpha Traveling Waves in Visual Contrast Detection.

The intricate relationship between prestimulus alpha oscillations and visual contrast detection variability has been the focus of numerous studies. However, the causal impact of prestimulus alpha traveling waves on visual contrast detection remains largely unexplored. In our research, we sought to discern the causal link between prestimulus alpha traveling waves and visual contrast detection across different levels of mental fatigue. Using electroencephalography alongside a visual detection task with 30 healthy adults (13 females; 17 males), we identified a robust negative correlation between prestimulus alpha forward traveling waves (FTWs) and visual contrast threshold (VCT). Inspired by this correlation, we utilized 45/-45° phase-shifted transcranial alternating current stimulation (tACS) in a sham-controlled, double-blind, within-subject experiment with 33 healthy adults (23 females; 10 males) to directly modulate these alpha traveling waves. After the application of 45° phase-shifted tACS, we observed a substantial decrease in FTW and an increase in backward traveling waves, along with a concurrent increase in VCT, compared with the sham condition. These changes were particularly pronounced under a low fatigue state. The findings of state-dependent tACS effects reveal the potential causal role of prestimulus alpha traveling waves in visual contrast detection. Moreover, our study highlights the potential of 45/-45° phase-shifted tACS in cognitive modulation and therapeutic applications.

Transient anterior subcapsular vacuolar lens opacities after Tanito microhook trabeculotomy: report of six cases

ObjectiveTo present six cases exhibiting transient anterior subcapsular vacuolar lens opacities following early postoperative Tanito microhook trabeculotomy (TMH) performed by the same surgeon.MethodsSix patients who underwent lens-sparing TMH at Meizankai Shimizu Eye Clinic from November 2021 to May 2023, and developed anterior subcapsular vacuolar lens opacities postoperatively were reviewed. Detailed records of surgeries, follow-up findings were collected and reported.ResultsIn all six cases, anterior vacuolar subcapsular lens opacities were observed on the day after surgery, gradually decreasing without affecting visual acuity or contrast sensitivity. In all cases, without any specific interventions, the opacities disappeared by 21 months postoperatively.ConclusionAnterior subcapsular cataracts, characterized by a vacuolar appearance and transient existence, should be recognized as an early complication of ab interno glaucoma surgery, possibly linked to use of distributed ophthalmic viscosurgical devices and excessive anterior chamber irrigation leading to traumatic cataracts on the lens surface.

Does a cautious driving style reduce the crash risk of older drivers? An analysis using a novel driving style recognition method

Older drivers who are aware of their declining functions tend to adopt a cautious driving style to compensate for their declining driving abilities. However, whether cautious older drivers are associated with a reduced crash risk has not been well studied. In this study, we examined the association between older drivers’ cautious driving style and crash risk using a novel driving style recognition method. We proposed a driving style recognition method that does not require predefined thresholds and applied it to the driving data of 71 drivers comprising 59 drivers aged 65 years or older (mean age 72.4; 67.8 % male) and 12 drivers aged 51–64 years (mean age 58.3; 66.7 % male). Drivers were classified into cautious and relatively aggressive groups based on the classification results of their speed, acceleration, and braking styles. The results showed that cautious drivers were characterized by older age, poorer Trail Making Test Part B performance, less frequent night driving, and lower driving exposure, indicating that older drivers may adopt multiple compensatory strategies. Although the crash involvement rate of cautious older drivers was approximately half that of relatively aggressive drivers, the difference was not statistically significant. Furthermore, this difference was expected to decrease when driving exposure was considered. Older drivers who adopted a cautious driving style but were involved in traffic crashes had poorer visual acuity and contrast sensitivity. The results of this study indicate that a cautious driving style alone may not be sufficient to compensate for older drivers’ declining functions, particularly the loss of two visual functions observed in the present study.

Exploring Binocular Visual Attention by Presenting Rapid Dichoptic and Dioptic Series.

This study addresses an issue in attentional distribution in a binocular visual system using RSVP tasks under Attentional Blink (AB) experimental protocols. In Experiment 1, we employed dichoptic RSVP to verify whether, under interocular competition, attention may be captured by a monocular channel. Experiment 2 was a control experiment, where a monoptic RSVP assessed by both or only one eye determines whether Experiment 1 monocular condition results were due to an allocation of attention to one eye. Experiment 3 was also a control experiment designed to determine whether Experiment 1 results were due to the effect of interocular competition or to a diminished visual contrast. Results from Experiment 1 revealed that dichoptic presentations caused a delay in the type stage of the Wyble's eSTST model, postponing the subsequent tokenization process. The delay in monocular conditions may be further explained by a visual attenuation, due to fusion of target and an empty frame. Experiment 2 evidenced the attentional allocation to monocular channels when forced by eye occlusion. Experiment 3 disclosed that monocular performance in Experiment 1 differs significantly from conditions with interocular competition. While both experiments revealed similar performance in monocular conditions, rivalry conditions exhibit lower detection rates, suggesting that competing stimuli was not responsible for Experiment 1 results. These findings highlight the differences between dichoptic and monoptic presentations of stimuli, particularly on the AB effect, which appears attenuated or absent in dichoptic settings. Furthermore, results suggest that monoptic presentation and binocular fusion stages were a necessary condition for the attentional allocation.

Storz professional image enhancement system (SPECTRA A) enhancing detection of carcinoma urinary bladder by white light cystoscopy

BackgroundSPECTRA A filters red light from white light through software to create contrast for better tissue visualization and light penetration. We aim to find whether the detection rate of bladder cancer is enhanced by SPECTRA A in adjunct to White Light Cystoscopy (WLC).MethodsThis was a prospective observational study among 66 patients in the Department of Urology and Kidney Transplant Surgery, Tribhuvan University Teaching Hospital. All patients undergoing TURBT for suspected/diagnosed bladder tumor were evaluated with WL, followed by SPECTRA A mode, and findings were recorded using visual bladder mapping. Resection of the tumor was done on WL, margins were again reevaluated using SPECTRA A mode, and a biopsy was taken in cases of suspicious findings confirmed on SPECTRA A. Tumor detection rate (sensitivity), extra lesion detection, false positive rate, and margin status were evaluated through 2 × 2 tables, McNemar chi-square test on patient level as well as lesion level.ResultsA total of 64 patients were included in the study. The mean age was 62.20 ± 13.98 with a sex ratio of M:F 4.3:1. SPECTRA A and WL had a detection rate of 95.33% and 78.80% (p = 0.001), respectively, and positive biopsy of detected lesions was 78.8% and 84.13% (p = 0.041), respectively, for SPECTRA A and WL. The false positive rate of SPECTRA A and WL was 21.19% and 15.86% (p = 0.006), respectively, whereas the false negative rate was 4% and 19.2% (p = 0.001), respectively. The number of extra lesions detected by SPECTRA A was 39, out of which 29 were histologically proven tumors.ConclusionSPECTRA A enhances the detection rate of bladder cancer when used with WL. We can increase the detection of bladder cancer by using a combination of white light and SPECTRA A.

Performance on clinical outcomes, activities of daily living anduser experience on head-mounted displays for people withvision impairment.

To compare the objective performance, acceptance and usability of head-mounted displays (HMDs) to provide evidence-based data that could be used to increase the efficiency of device referrals based upon a person's vision loss and functional needs. A cross-sectional, counterbalanced, individually controlled crossover study was performed on 15 adults with various eye conditions. Performance was measured when using four HMDs: eSight4, Eyedaptic EYE3, Eyedaptic EYE4 and IrisVision Inspire. Performance on clinical visual acuity tests and contrast were assessed, as well as vision-related activities of daily living (ADL) which were divided into three categories: Reading, Searching & Identifying and Eye-hand Coordination. User-experience was also assessed. Logistic regression analyses, Friedman one-way repeated measure analyses of variance by ranks and multivariate permutation testing were used for analysis. There was a significant improvement in visual acuity when using all devices. For contrast tasks, only the eSight4 and Eyedaptic EYE3 improved performance relative to baseline. For most Reading and Searching & Identifying tasks, the odds of being able to perform the tasks were significantly higher while using the devices. However, the actual performance with most devices (e.g., number of words read or reading speed) did not improve significantly over baseline for most tasks. For the Eye-hand Coordination tasks, participants performed equivalent to or significantly poorer than baseline when using the devices. No demographic or clinical predictors of outcomes were identified. Participants expressed dissatisfaction with the devices' effectiveness, acceptability and usability. While performance on clinical tests was better when using the devices, performance on most real-world ADLs was equal to or worse than baseline. No single device improved performance on all tasks, and performance on any one task was not improved with all the devices. The overall dissatisfaction with the devices paralleled the lack of objective improvement in the performance of real-world tasks.

Evaluation of the effects of blue-enriched white light on cognitive performance, arousal, and overall appreciation of lighting.

Light's non-visual effects on the biological clock, cognitive performance, alertness, and mental health are getting more recognized. These are primarily driven by blue light, which triggers specific retinal cells containing melanopsin. Traditionally, research on light has relied on correlated color temperature (CCT) as a metric of its biological influence, given that bluer light corresponds to higher Kelvin values. However, CCT proves to be an inadequate proxy of light's biological effects. A more precise metric is melanopic Equivalent Daylight Illuminance (mel-EDI), which aligns with melanopsin spectrum. Studies have reported positive cognitive impacts of blue-enriched white light. It's unclear if the mixed results are due to different mel-EDI levels since this factor wasn't assessed. Given recent recommendations from experts to aim for at least 250 mel-EDI exposure daily for cognitive benefits, our aim was to assess if a 50-minute exposure to LED light with 250 mel-EDI could enhance concentration and alertness, without affecting visual performance or comfort compared to conventional lighting producing around 150 mel-EDI. To ensure mel-EDI's impact, photopic lux levels were kept constant across conditions. Conditions were counterbalanced, parameters included subjective sleepiness (KSS; Karolinska Sleepiness Scale), concentration (d2-R test), visual performance (FrACT; Freiburg Visual Acuity and Contrast Test), general appreciation (VAS; Visual Analogous Scale), preferences and comfort (modified OLS; Office Lighting Survey). The experimental light significantly reduced sleepiness (p = 0.03, Cohen's d = 0.42) and also decreased contrast sensitivity (p = 0.01, Cohen's d = 0.50). The conventional light was found to be more comfortable (p = 0.002, Cohen's d = 0.62), cheerful (p = 0.02, Cohen's d = 0.46) and pleasant (p = 0.005, Cohen's d = 0.55) while the experimental light was perceived as brighter (p = 0.004, Cohen's d = 0.58) and tended to be more stimulating (p = 0.10). Notably, there was a preference for conventional lighting (p = 0.004, Cohen's d=0.56) and concentration was equally improved in both conditions. Despite the lack of further improvement in concentration from exposure to blue-enriched light, given the observed benefits in terms of vigilance, further research over an extended period would be justified. These findings could subsequently motivate cognitive optimization through lighting for workers that would benefit from artificial lighting such as in northern regions.

Bioavailability of Lutein from Marigold Flowers (Free vs. Ester Forms): A Randomised Cross-Over Study to Assess Serum Response and Visual Contrast Threshold in Adults.

Lutein (Lut) and zeaxanthin (Zeax) are found in the blood and are deposited in the retina (macular pigment). Both are found in the diet in free form and esterified with fatty acids. A high intake and/or status is associated with a lower risk of chronic diseases, especially eye diseases. There is a large global demand for Lut in the dietary supplement market, with marigold flowers being the main source, mainly as lutein esters. As the bioavailability of Lut from free or ester forms is controversial, our aim was to assess the bioavailability of Lut (free vs. ester) and visual contrast threshold (CT). Twenty-four healthy subjects (twelve women, twelve men), aged 20-35 and 50-65 years, were enrolled in a cross-sectional study to consume 6 mg lutein/day from marigold extract (free vs. ester) for two months. Blood samples were taken at baseline and after 15, 40, and 60 days in each period. Serum Lut and Zeax were analysed using HPLC, and dietary intake was determined with a 7-day food record at the beginning of each period. CT, with and without glare, was at 0 and 60 days at three levels of visual angle. Lut + Zeax intake at baseline was 1.9 mg/day, and serum lutein was 0.36 µmol/L. Serum lutein increased 2.4-fold on day 15 (up to 0.81 and 0.90 µmol/L with free and ester lutein, respectively) and was maintained until the end of the study. Serum Zeax increased 1.7-fold. There were no differences in serum Lut responses to free or ester lutein at any time point. CT responses to lutein supplementation (free vs. ester) were not different at any time point. CT correlated with Lut under glare conditions, and better correlations were obtained at low frequencies in the whole group due to the older group. The highest correlations occurred between CT at high frequency and with glare with serum Lut and Lut + Zeax. Only in the older group were inverse correlations found at baseline at a high frequency with L + Z and with Lut/cholesterol and at a low frequency with Lut/cholesterol. In conclusion, daily supplementation with Lut for 15 days significantly increases serum Lut in normolipemic adults to levels associated with a reduced risk of age-related eye disease regardless of the chemical form of lutein supplied. Longer supplementation, up to two months, does not significantly alter the concentration achieved but may contribute to an increase in macular pigment (a long-term marker of lutein status) and thus improve the effect on visual outcomes.

Functional MR elastography measures visual cortex stiffening proportional to visual contrast intensity in regions of activation

Abstract Functional MRI (fMRI) is widely used to spatially localize neural activity in the brain associated with functional stimuli. Functional MR Elastography (fMRE) has recently been introduced as a complementary approach that measures the mechanical response to functional stimulus. The hypothesis of the current study is that the stiffness change in fMRE is proportional to the underlying neural activity. This hypothesis is tested by measuring the median stiffness change in the visual cortex as a function of luminance-matched contrast intensity of a checkerboard visual stimulus in 16 healthy subjects. The fMRE signal in the visual cortex was observed to be proportional to the contrast intensity of the visual stimulus. In regions of activation, fMRE signal increased in the range of 2 ± 1% to 5.8 ± 1% and fMRI signal increased by the expected 0.4 ± 0.2% to 0.9 ± 0.2%, for contrast levels of 5% to 100%, respectively. In conclusion, this study shows that the fMRE signal in the visual cortex can be directly modulated by the contrast intensity of a visual stimulus. The presence of some overlap between fMRI and fMRE regions of activation may suggest two distinct mechanisms governing the fMRI and fMRE signals, which will be investigated in future studies.

Enhancing Power Lines Detection Using Deep Learning and Feature-Level Fusion of Infrared and Visible Light Images

AbstractThe detection of power lines is critical for flight safety, especially for drones and low-flying aircraft. Power line detection models help prevent collisions, reducing potential damage and preserving lives, while also safeguarding critical infrastructure. This has led to significant research efforts to develop accurate detection models. In this study, we employ paired infrared–visible power line datasets to train three distinct deep learning models. The first two models are sequential deep learning models based on VGG16 and AlexNet networks. They are tailored for detection in visible images, while they were optimized again for infrared images. For the third model, we introduce an innovative deep learning architecture utilizing Functional Application Programming Interface, affording us the flexibility to construct a multi-input model with shared layers. Our proposed model accepts paired images (visible and infrared) as inputs. Then, a feature-level fusion process is applied to merge the extracted features from both inputs and generate an enriched feature map. This approach amalgamates the advantages of visible images, which boast high resolution and rich texture features, with infrared images, which excel in high contrast and clear vision under adverse environmental conditions. Comparing the outcomes of the three models, our proposed model emerges as the front runner, boasting an impressive accuracy rate of 99.37%. Moreover, real-time processing was adopted by conducting ablation experiments to optimize the model and reduce the number of trainable parameters, resulting in an inference speed of 2.7 milliseconds per frame.

Visual function after ultrathin Descemet’s stripping automated endothelial keratoplasty or Descemet’s membrane endothelial keratoplasty combined with cataract surgery: a randomised controlled clinical trial

AimsTo compare best-corrected visual acuity (BCVA), contrast sensitivity and endothelial cell density (ECD) after ultrathin Descemet’s stripping automated endothelial keratoplasty (UT-DSAEK) and Descemet’s membrane endothelial keratoplasty (DMEK).MethodsA randomised, single-blinded, single-centre...

Salinity Fronts in the South Atlantic

Monthly climatology data for salinity fronts in the South Atlantic have been created from satellite SMOS sea surface salinity (SSS) measurements taken from 2011–2019, processed at the Barcelona Expert Center of Remote Sensing (BEC), and provided as high-resolution (1/20°) daily SSS data. The SSS fronts have been identified with narrow zones of enhanced horizontal gradient magnitude (GM) of SSS, computed using the Belkin–O’Reilly algorithm (BOA). The SSS gradient fields generated by the BOA have been log-transformed to facilitate feature recognition. The log-transformation of SSS gradients markedly improved the visual contrast of gradient maps, which in turn allowed new features to be revealed and previously known features to be documented with a monthly temporal resolution and a mesoscale (~100 km) spatial resolution. Monthly climatologies were generated and analyzed for large-scale open-ocean SSS fronts and for low-salinity regions maintained by the Rio de la Plata discharge, Magellan Strait outflow, Congo River discharge, and Benguela Upwelling. A 2000 km-long triangular area between Africa and Brazil was found to be filled with regular quasi-meridional mesoscale striations that form a giant ripple field with a 100 km wave length. South of the Tropical Front, within the subtropical high-salinity pool, a trans-ocean quasi-zonal narrow linear belt of meridional SSS maximum (Smax) was documented. The meridional Smax belt shifts north–south seasonally while retaining its well-defined linear morphology, which is suggestive of a yet unidentified mechanism that maintains this feature. The Subtropical Frontal Zone (STFZ) consists of two tenuously connected fronts, western and eastern. The Brazil Current Front (BCF) extends SE between 40 and 45°S to join the subantarctic front (SAF). The STFZ trends NW–SE across the South Atlantic, seemingly merging with the SAF/BCF south of Africa to form a single front between 40 and 45°S. In the SW Atlantic, the Rio de la Plata plume migrates seasonally, expanding northward in winter (June–July) from 39°S into the South Brazilian Bight, up to Cabo Frio (23°S) and beyond. The inner Plata front moves in and out seasonally. Farther south, the Magellan Strait outflow expands northward in winter (June–July) from 53°S up to 39–40°S to nearly join the Plata outflow. In the SE Atlantic, the Congo River plume spreads radially from the river mouth, with the spreading direction varying seasonally. The plume is often bordered from the south by a quasi-zonal front along 6°S. The diluted Congo River water spreads southward seasonally down to the Angola–Benguela Front at 16°S. The Benguela Upwelling is delineated by a meridional front, which extends north alongshore up to 20°S, where the low-salinity Benguela Upwelling water forms a salinity front, which is separate from the thermal Angola–Benguela Front at 16°S. The high-salinity tropical water (“Angola water”) forms a wedge between the low-salinity waters of the Congo River outflow and Benguela Upwelling. This high-salinity wedge is bordered by salinity fronts that migrate north–south seasonally.